"Colorado's renewable portfolio standard is helping to drive new and substantial developments of renewable energy projects. This week, a company named Greenlight Energy received approval from the Washington County Commission to develop a large-scale wind farm near the town of Akron that could provide enough clean energy to meet the annual needs of up to 90,000 homes." http://renewableenergyaccess.com/rea/news/story?id=34089
"The area near Thuringer and Franconia, about half way between Berlin and Munich, has escaped progress for the 45 of the last 60 years because it was a Communist country until 1989, and thus the towns are much more picturesque, quaint and old German than the rest. This nation has committed itself at great cost towards preserving its historic sites, and Germany is as homogeneous as any country on earth... But unlike Cape Cod, where our political leaders are attempting to block a wind farm in front of "landmarks" like Nobska Lighthouse and the Kennedy Compound, Germany installs their wind farms wherever the winds blows, even when it blows in front of that nation's equivalent to the Statue of Liberty." http://www.capecodtoday.com/modules.php?op=modload&name=News&file=article&sid=0181
"June 23, 2005. Wind power subsidy survives. The U.S. Senate last night soundly rejected a measure intended to curtail the development of wind farms in scenic and coastal areas such as Cape Cod... Massachusetts Sens. Edward Kennedy and John Kerry joined nearly all the Senate's Democratic members in voting against the measure... Neither Kennedy nor Kerry participated in the debate prior to last night's vote... In the past, Kennedy has stated his opposition to Cape Wind. Kerry's vote is the closest the senator has come to date in stating where he stands on Cape Wind. In the 3½ years since it was first proposed, he has repeatedly declined to say whether he favors the offshore project." http://www.capecodonline.com/cctimes/windpower23.htm
The AWEA website's FAQ has a table on wind potential in the windier US states. For reference, the US electricity production (which due to losses is usually higher than consumption unless there is significant net import) is 4,000 terawatt-hours (TWh) per year, and generating capacity gets close to 1,000 GW - so there you already see a potential exceeding demand.
However, this table, like the entire FAQ, is a bit outdated (the table is 1991 data). For an up-to-date estimate, I'll do some calculation. I start from this Stanford study, which looked for wind potential at higher altitudes than earlier studies, in line with the increase of wind turbine tower height since. They found "that U.S. windpower at 80 m may be substantially greater than previously estimated. It was found that 21% of all stations (and 39% of all coastal/offshore stations) are characterized by mean annual speeds >=6.9 m/s at 80 m, implying that the winds over possibly one fifth of the U.S. are strong enough to provide electric power at a direct cost equal to that of a new natural gas or coal power plant."
That's about 2 million square kilometres. Now, assuming 2 MW turbines which are placed at a typical density of 3.5/km^2, and which all produce only 4.4 million kWh at a 25% average power, the full potential would be 30.8 TWh per year, and 14,000 GW. That is, an eighth of the one fifth of the US land sureface suitable for wind power development (or less than 3% of all) would be enough - and that can be done easily even if inhabited areas, natural reserves, bird-nesting areas and bird migration routes are avoided. *Lunatic*, n. One whose delusions are out of fashion.
Of course, I meant to say, the full potential would be 30,800 TWh per year, and that with a maximum generating capacity of 14,000 GW. *Lunatic*, n. One whose delusions are out of fashion.
But it does look pretty good. And taller towers would even be better, I suppose. Now all we need to do is figure out how to get our "most liberal senators in the country" to support it! :-)
However, you still have a point, I submit transmission losses (and costs) would probably rise. But the issue is uneven production, which is worth a separate treatment.
The first point about uneven production should be that it is not a problem for today. Due to the small size of an individual plant, short-term fluctuations are levelled with multiple parks on the local grid, while for slower changes due to weather, there is plenty of spare capacity to compensate - the reserve capacity already kept for peak hours or to jump in for a major, say a nuclear power plant that malfunctions(). But should wind achieve a larger segment of the electricity production, something more is needed. One possibility is to organise the power system on very large scales, so that entire weather zones (say from front to front) are covered, and it is always possible for electricity from wind parks that happen to have strong winds to be transferred to areas with low winds. Another possibility is energy storage. The most obvious way (and one applied on a smaller scale by Denmark in cooperation with Sweden and Norway) is to use hydroelectric power passively - i.e., regulate power (and thus water) output in opposition to wind power and in line with demand. There is also pumped storage: excess electricity from wind power used to pump water from a lower reservoir to a higher one, and let it back through turbines when wind is low. There are experiments with another kind of pumped storage: air into disused mines. Maybe others read of further technologies and can supplement. Finally, since we are speaking about something whose need arises over decades, there is the possibility of combination with photovoltaics. The typical daily output curves of wind power and PV can be combined to roughly match the double-peaked curve of human consumption, and there is also a rough compensation for weather dependencies. So if non-crystalline, non-rare-metals PV cells (especially film cells that can be applied to a great variety of surfaces and can have different colours to solve problems of aesthetics) can be made cheaper (something researchers promise), the age of truly decentralised energy production could come. () OK, recent events suggest that in some US regions or Italy, this may not be the case - but then, this is a problem to be solved anyway. *Lunatic*, n. One whose delusions are out of fashion.
But should wind achieve a larger segment of the electricity production, something more is needed. One possibility is to organise the power system on very large scales, so that entire weather zones (say from front to front) are covered, and it is always possible for electricity from wind parks that happen to have strong winds to be transferred to areas with low winds.
Another possibility is energy storage. The most obvious way (and one applied on a smaller scale by Denmark in cooperation with Sweden and Norway) is to use hydroelectric power passively - i.e., regulate power (and thus water) output in opposition to wind power and in line with demand. There is also pumped storage: excess electricity from wind power used to pump water from a lower reservoir to a higher one, and let it back through turbines when wind is low. There are experiments with another kind of pumped storage: air into disused mines. Maybe others read of further technologies and can supplement.
Finally, since we are speaking about something whose need arises over decades, there is the possibility of combination with photovoltaics. The typical daily output curves of wind power and PV can be combined to roughly match the double-peaked curve of human consumption, and there is also a rough compensation for weather dependencies. So if non-crystalline, non-rare-metals PV cells (especially film cells that can be applied to a great variety of surfaces and can have different colours to solve problems of aesthetics) can be made cheaper (something researchers promise), the age of truly decentralised energy production could come.
(
- High fatality rate associated with dam failures. Hydro power rates poorly by this metric. http://www.uic.com.au/ne6.htm
- Environmentalist non-acceptance. The dam at Lake Pedder in Tasmania was what triggered the birth of the Green Party. Hydro-electric power requires dams on beautiful undeveloped wilderness, but pumped storage is worse because it uses dams on lakes that don't even have stable beaches.
BTW, the picture Jérôme has chosen shows the ex NEG-Micon, now Vestas NM-110, a 4.2MW, 110 m rotor diameter, 100 m hub height prototype for off-shore turbines, erected at the Risø test field in Denmark. (One German series unit and two prototypes are larger than that, and Vestas's series model - the V-120 - will also be larger.) *Lunatic*, n. One whose delusions are out of fashion.
http://www.multibrid.com/english/index.html
The other is REpower's REpower 5M, another 5 MW unit but with more traditional technology.
The one giant in series production I mentioned (five in service, three in construction) is Enercon's E-112, a 4.5 MW critter. Enercon is the leading German manufacturer, they pioneered gearless turbines - which are more silent -, and were the first to aim towards 5 MW. However, on the low side, their unit has the largest head weight [weight of generator & its house, nacelle, and blades] among these giants - just compare the image below to Jérôme's NM-110 image.
One nearshore and two on-shore E-112s in construction (the latter two are the closest in the wind park in background, the one to the right without head yet) *Lunatic*, n. One whose delusions are out of fashion.
However, there are currently no Enercon turbines working or being built in the USA. Either that was an inofficial part of the agreement, or local connections have their effect. Even in Canada, they sold just a single turbine. *Lunatic*, n. One whose delusions are out of fashion.
Enercon has a very different technology from other manufacturers, and they do everytyhing in house. It's generally considered to be a highly reliable technology, but hte company will face the same problem as Vestas, i.e. they are seen as too small to provide the necessary financial guarantees (to back up their technical performance commitments over a number of years) for the increasingly big projects that are being developed, and it is not clear ho long they will manage to remain independent. In the long run, we're all dead. John Maynard Keynes
